Project Summary/Abstract Heart disease is a leading cause of death in the US and obesity is an important risk factor. While cardiometabolic diseases have peak prevalence in adulthood, the assessment of cardiometabolic risk processes in childhood is critical in order to define the early causal factors that contribute to the development of chronic disease and to identify potential pathways for prevention. Previous studies have shown that traditional cardiometabolic risk factors (e.g., hypertension) track from childhood into adulthood. Socioeconomic disadvantage and psychosocial stressors have also been linked to obesity in childhood and to later risk of cardiovascular disease. However, a major knowledge gap remains in understanding how environmental, behavioral, and biological contexts interact to influence cardiometabolic risk in the developing child and influence later disease outcomes. The proposed study will examine the relationship between early environmental stressors and emerging cardiometabolic risk by extending a unique cohort of 534 racially/ethnically diverse, predominantly low income children who have been studied longitudinally since they were 2-4 years of age [The NET-Works Trial (U01HD068890; Sherwood/French PIs), part of the COPTR consortium (Child Obesity Prevention and Treatment Research Consortium, NIH/NHLBI/DCVS/PPSP)]. The overall goal of the proposed study is to characterize the emergence of dysregulation in cardiometabolic processes in a high-risk cohort of children at 7-9 years of age, and elucidate the pathways through which early environmental stressors influence cardiometabolic risk. Four existing measurement time points provide rich information about psychosocial stressors in children's homes and neighborhoods, physiological measures of children's stress (cortisol levels from hair samples), and patterns of children's health behavior. New data collection when children are 7-9 years of age will add a comprehensive state-of-the-science cardiometabolic assessment. Specifically, this study will (1) establish and quantify the independent influence of and interaction between home and neighborhood environmental stressors in early childhood on cardiometabolic risk in middle childhood and (2) examine the role of children's health behaviors (i.e., physical activity, dietary intake, and screen time) and cortisol levels in emerging cardiometabolic risk, and determine whether health behaviors and cortisol mediate the relationship between environmental stressors and cardiometabolic risk. This prospective, multi-component approach to measuring early environmental stressors and emerging cardiometabolic risk processes, at a developmental stage when precursors of cardiometabolic disease can begin to be observed but before the manifestation of overt disease, will help us define early causal factors that set the stage for later development of adult chronic conditions.